A comparison of the activity of ciprofloxacin and levofloxacin with other agents against respiratory tract pathogens.

In a study involving 15 UK hospitals, sequential respiratory tract isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were studied. The susceptibility of these strains to two fluoroquinolones, ciprofloxacin and levofloxacin were compared to those of currently used macrolides and beta-lactams. The activity of ciprofloxacin and levofloxacin against S. pneumoniae was not statistically significantly different (geometric mean MIC 0.978 and 0.95 mg/L respectively). Beta-lactam resistance did not affect fluoroquinolone susceptibility. H. influenzae and M. catarrhalis were highly susceptible to both fluoroquinolones.